Large-Signal Stabilization of Interleaved Multilevel Boost Converter Interfaced High Power DC Microgrid Using an Adaptive Observer Based Nonlinear Control Scheme

The features of low current ripple and high voltage gain make the interleaved multilevel boost converter (IMBC) a promising topology to link low-voltage and high-power energy sources and the DC bus of the microgrid (MG). Considering the modern DC MG is highly penetrated by the constant power loads that threaten the system stability, a large-signal stabilization scheme for the IMBC-based DC MG is proposed in this paper. An adaptive sliding mode observer (ASMO) is developed to estimate both matched and mismatched disturbances and, further, improve the control performance. Since the knowledge of the bounds of the disturbances and their derivatives is not required in the ASMO, a wide range of disturbances can be estimated. In addition, a unified reduced-order state-space model of the IMBC is derived to facilitate the design of the proposed control law. Moreover, a novel phase current balancing compensator (PCBC) is designed to balance the input phase currents of the IMBC. Finally, simulation and experimental results are demonstrated to show the effectiveness of the proposed method.